Preparation of perfumes



March 13, 1962 E. c. KUNZ ETAL 3,025,220

PREPARATION PERFUMES Filed Dec. 12. 1956 2 Sheets-Sheet 1 Light, Aldehydic Perfume Heavy Oriental Perfume INVENTORS 2 Sheets-Sheet 2 E. C. KUNZ ETAL PREPARATION PERFUMES March 13, 1962 Filed Dec.

IN V EN TORS United Stats 3,025,220 PREPARATION OF PERFUMES Eric C. Kunz, Dr. Kunz Farm, Fletcher, N.C., and Dale Eusminger, Columbus, Ohio; said Ensminger assignor to said Kunz Filed Dec. 12, 1956, Ser. No. 627,788 6 Claims. (Cl. 167-94) This invention relates to the art of perfumes and is directed more particularly to a simple and highly inexpensive process by means of which the odiferous characteristics of perfume materials may be altered, modified, and, in general, improved.

Perfumery is among the most ancient of arts, dating back, perhaps, as far 'as recorded civilization itself. While many of the natural perfume chemicals, such as oil of rose and oil of cloves, still are used today in a form probably unchanged from that, say, of the days of Cleopatra, in more recent years research chemists have made a tremendous impact upon the industry by discovering a large number of new synthetic odiferous chemicals possessing characteristics desired in the art. Modern science has, thus, greatly added to the store of materials available to the perfumer and has multiplied the combinations that can be made; nevertheless, it has had very little influence upon the technique by which perfumes are created. This task remains the role of one with highly developed olfactory perception and years of experience who, by skillful choice and the careful blending of ingredients selected from the vast array available to him and guided only by rule of thumb and trial and error, patiently labors until just the right combination having the desired qualities has been achieved. In short, perfumes are, indeed, a creation rather than a manufacture, and the successful perfumer is an artist rather than a workman. The efforts of the perfumer are further complicated by the fact that his judgment is not supreme but, in the final analysis, is subservient to the constantly shifting taste of the consuming public. Even though he may have spent many months just to perfect a product to a point where it is, in his opinion, outstanding, unless that product gains the approval of the buying public, he will, in the practical sense, have failed. Many instances are known of perfumes that were accepted in certain countries or localities but were rejected in others.

In spite of the contribution of chemical research in adding to the tools to the trade, perfumery has remained largely unamenable to mechanization. Recently, a method of converting citronellol to rhodinol by ultraviolet rays was proposed in Patent 2,679,476, but this is an isolated instance and the technique is presumably applicable only to this specific material. Because of this lack of mechanization, the perfumer must still exercise his talent in combining and compounding the various perfume chemicals, which, while many in number, are still fixed and unchangeable as to odiferous characteristics. This is to say, that variation or alteration in scent quality of a perfume or mixture of perfumes has hitherto been accomplished only by the addition of a further ingredient or ingredients having the desired contrasting, supplementing or complementing qualities. No technique has been available by means of which a given perfume, whether composed of one or more ingredients,

could have its scent characteristics permanently and significantly changed so that an initially unacceptable perfume itself could be converted into a desirable prodnot. Such a technique has now been discovered and constitutes the subject matter of the present invention.

In brief, the present invention comprehends the treatment of perfume chemicals, whether alone or in combination, to vibrations or waves having a frequency within the sonic or ultrasonic ranges.

Before discussing the details of the invention, it might be Well to mention the general characteristics that are desired in an acceptable perfume, which will also serve to define certain terms of the art that will be encountered in this specification. First of all, a good perfume should have an agreeable top note, that is, a scent fraction that in a profusive way properly penetrates the surrounding environment largely for the purpose of calling attention to its presence, or, more precisely, the presence of its wearer. Next, it should possess body, that is, possess a quality of substance rather than being weak and insipid. It should diffuse in an even note," that is, the scent characteristics should not change significantly as the perfume is diluted by the atmosphere. Further, both the middle note and the end note should be pleasant, that is, the less volatile fractions which appear after the perfume has been exposed to the atmosphere for a time should be perfumes of quality in themselves, although it is not necessary, or even desirable, that these later notes have the exact characteristics of the top note. Finally, a good perfume must have an extended lasting power so that its fragrance does not quickly disappear.

As far as it can be determined, virtually any perfume chemical responds to a more or less degree to treatment in accordance with the present invention. Thus, mention may be made of those chemicals which are of a synthetic nature, such as the alcohols, aldehydes, ketones, lact-ones, ethers and esters, as well as the natural odiferous products of vegetable or animal origin, such as derived from fruits, woods, leaves, roots, blossoms, mosses or lichens, exudations, bodily organs or the products of such organs. Such materials may be used in their raw state or extraction, either with or without the medium by means of which they were extracted, in a semi-refined or highly refined state, in the form of [fractions thereof or in the form of isolated chemicals in a more or less pure form.

Specific examples of these materials are the flower oils, such as rose and jasmin; the essential oils, such as oil of geranium and oil of bergamot; the citrus oils; ambergris; oleo resins extracted from beaver pods and civet as well as the various derivatives and products of refinement, such as rhodinol from geranium bourbon, geraniol from the citronellas, linalool from bois de rose Cayenne, and many others, either alone or in any degree of admixture with others.

It may be mentioned that the use of the term purity in connection with perfume chemicals is intended to mean odor pure rather than chemically pure since certain perfume ingredients, the higher aliphatic aldehydes, for example, possess more desirable scent characteristics in a less refined form in flavors than when refined to a high state of chemical purity.

The use of the term perfume" in this specification and the accompanying claims is not intended to exclude classes of odiferous materials which are used more frequently, or even exclusively, as flavorings than as perfumes in the strict sense of the word, such as the oil of lemon, orange, clove, or strawberry among many others. Quite obviously there is little, if any, distinction in fact between odiferous perfume chemicals and odiferous flavoring chemicals.

As might be expected, the changes that were effected on the stable synthetic products, such as benzyl alcohol, benzo phenone, or benzyl acetate, were not as great or noticeable as on the products derived from less stable materials, such as the essential oils and their derivatives. However, experiments have been performed using a wide variety of perfume chemicals and it can be said that detectable differences in odor characteristics were observed in virtually every case.

It is preferred that the treatment he carried out on ingredients or mixtures thereof which are in liquid form. Where the ingredients are naturally liquid in form, they may be used as such, or the naturally liquid materials, as well as the solid materials, may be diluted by or dissolved in an appropriate solvent. The simplest and most readily available of such solvents is, of course, ethyl alcohol, preferably of high concentration although other concentrations are not excluded. The grade of dilution or the amount of solvent employed may be widely varied. Obviously, in addition to ethyl alcohol, any other solvent or diluent known to be compatible with the particular material or materials being treated will be suitable, an example being diethyl phthalate.

There are a number of variables involved in the treatment of the present invention. First, and one of the most important is, quite naturally, the intensity of the vibrations. The formula for the intensity I is:

where p is the density of the medium through which the sound wave travels, c is the velocity of sound in the medium, the amplitude, and w is 211' times the frequency. From this formula, it can be seen that the intensity takes into consideration both the frequency and amplitude. For the purposes of this invention, it appears that intensity is directly correlated with the time or duration of the treatment. In other words, the extent of the modification of the scent quality of the perfume raw material is a function of intensity and time and, as either or both of these variables is increased, the change observed in the raw material is also increased. Also, a lower intensity for a longer period of time will attain substantially the same result as a higher frequency for a correspondingly shorter period of time. As a result of this correlation, it is difiicult to prescribe either the minimum or the maximum limits of these two variables, except to say that they are largely dictated by practical considerations. Since one of the principal advantages of the invention is the ability to effect a desired change within a relatively short period of time, it is usually preferred that the intensities be at least moderate. On the other hand, it is possible that under certain circumstances with certain raw materials it might be desirable to combine low intensity vibration with a natural aging process extending over a period of months. It can be said that experimental work has been performed at frequencies as low as 20,000 cycles per second with readily detectable changes and there is no reason, except for the practical considerations just mentioned, why even lower frequencies would not be suitable. Experience in the field of sonic vibrations indicates that it is only below 50 cycles per second that the period of vibration is long enough to prevent the stresses in the material being treated from building up to an effective level. In the ultrasonic range, experiments have been carried out at frequencies of one megacycle without any indication at all of a loss or change in the effectiveness of the treatment or that the upper limits had been achieved.

As is well known, the amplitude of a sound wave as contemplated by the above formula depends on the extent of movement of the generator, in this case the head of the transducer, which, in turn, varies with the current supplied to the generator.

As regards higher intensities, it should be pointed out that perfume chemicals are by their very nature rather delicate and fragile and their desirable scent qualities can be irrevocably damaged if subjected to unduly rough or harsh conditions. In other words, it is quite possible for the treatment to be overdone if the combination of intensity and time is unreasonable. At exactly what point this would occur would depend on the particular material at hand and the other factors involved, such as degree of dilution, etc., and can be determined only by experimentation.

The temperature of the material being subjected to vibrations also influences the results that are obtained in that a higher temperature generally accelerates the treatment and may lead, as well, to a somewhat different type of change. Experimental work has produced no evidence at all of any critical temperature or ranges of temperature and it is thus believed that the temperature may be varied, as desired, in accordance with the results that are to be attained. Since the raw materials are used in the form of solutions or fluid mixtures, the temperature should ordinarily not be permitted to drop below that at which all of the ingredients remain in solution. Similarly, perfume chemicals are inherently volatile, at least in part, and as the temperature is increased the danger of losing the more volatile constituents by evaporation also increases, and the temperature above the boiling point of the material, or if a mixture the boiling point of the minimum boiling component thereof, should be avoided.

A factor which apparently affects the quality or nature of the change effected in the perfume raw materials rather than the extent or degree of such changes is whether or not the vibration is carried out in the presence of oxygen or in at atmosphere including oxygen. For interesting and desirable changes to be effected, it is not essential that oxygen be present for, as will be seen from the further discussion, different and significant results have been obtained where the treatment was carried out in an inert atmosphere, such as nitrogen. The treatment can be carried out under such conditions as to produce cavitation, which is a well known phenomenon in operations of thi stype denoting a condition in the liquid adjacent to the transducer resembling boiling. Recent experiments of a general nature by others suggest that cavitation apparently has the effect of activating any oxygen present in a material being subjected to sonic and supersonic vibrations and, if this view is correct, cavitation should enhance the rate at which oxidation of the perfume raw material will proceed in those cases where oxidation is desired. The point at which cavitation can be expected to occur with a given material cannot be predicted with any degree of accuracy since it is a function of many of the other conditions employed, such as the intensity of the vibration, the characteristics of the diluent, the degree of dilution, the temperature and the pressure. It will appear sooner in a low boiling, low vapor pressure medium than in a high boiling, high viscosity medium. Even in the same medium with all conditions constant, it has been observed to produce tremendous action at the very beginning followed by a gradual lessening or diminution in the boiling action, due presumably to the loss, as cavitation continues, of dissolved gases. Where the effects of oxidation are to be excluded or prevented as much as possible, the treatment can be carried out in a nitrogen or other inert atmosphere, as has already been mentioned, and in the absence of water. Well-known stabilizers or anti-oxidants can be added in the small amounts usually recommended for analogous reactions. The presence of metallic catalysts do not seem to influence materially the treatment of the present invention.

Except where the conditions of the treatment were so extreme as to be obviously unreasonable, the products of numerous experiments performed under a wide variety of conditions were found to have taken on an olfactory quality which represented an improvement, quite distinct in some cases and less distinct but still perceptible in others, at least from the point of View of certain skilled perfumers. From what has already been said concerning the art of perfumery, it will be understood and appreciated that any attempt to describe or characterize the changes observed following treatment in accordance with this invention with any degree of precision or reproducibility would be impractical and presumptuous, if not utterly impossible. Opinions of odors and odor purities are founded on the more or less developed sense of smell or on the olfactory capabilities of the individual influenced to a greater or lesser degree by his preconceived personal likes and dislikes. Up to the present time, at least, there is no objective test available that is free from the human or personal element. Nevertheless, in order to give some idea, however vague, of what type and degree of changes and improvements can be expected, the following experiments are submitted. The equipment used was a Hypersonic Generator Model BU-20'4, manu factored by the Brush Electronics Co. of Cleveland, Ohio, having an input rating of 660 watts at 6.5 amps. of 115 volt, single cycle A.C. current and a nominal output rating of 250 watts with a frequency range of 100-1000 kc. and the companion Hypersonic Transducer Model BU305A. Such a transducer is formed of barium titanate molded into the shape of a bowl, the surfaces of which are coated with silver electrodes. The bowl is protected by a stainless steel container and is cooled by water coils around the inside surface. A test tube for the sample is supported at the center of the bowl. The output energy of the generator is indicated by a milliammeter which reads the current to the cathode of the oscillator.

EXAMPLE I One cc. of commercial geraniol, analyzing 92% pure geraniol, was placed in the test tube which was mounted in position in the transducer bowl, being immersed in ll /z inches of water. With the frequency fixed at 600 kc., and the cooling coils functioning, the output power was increased until the milliammeter read 38 and thereafter the amplifier was tuned to the resonant frequency of the transducer. At this point, a slight vibration emanating at the central focal point of the tube and radiating outwardly, was observed. Upon a further increase in the output to 175 milliamperes, cavitation was clearly observed. After five minutes treatment at this output, a change in the scent characteristics was observed, which change was accentuated upon a further exposure of five minutes. Further treatment did not appear to improve the quality of the product. A comparison between the original material and the product of minutes treatment by an expert perfumer resulted in the opinion that the treated product was more desirable, particularly as regards the top note. The slight weedy or terpeney character of the odor of the original material had disappeared and a full rosy geraniol had taken its place. The same change could not be duplicated by simple distillation techniques. A possible explanation was that the material had been relieved of adhering impurities.

EXAMPLES IIXVII A series of comparative experiments were performed in the same manner as Example I on various combinations of conditions and two diverse perfumes, the first being of the heavy oriental type. similar to Shalimar, and the second being of the light aldehydic type, similar to Chanel No. 5. The conditions of these experiments are summarized in Table I and the experiments were duplicated on each of the two perfumes. The products of certain of these experiments, which were considered repre sentative, were then compared by three expert perfumers. The products compared and the combined opinion of the experts are given in Table II.

Table No. I

EXPERIMENTAL CONDITIONS FOR SUPERSONIC TREAT MENT OF EXAMPLES II--XVII Concen- Cavlta- Tempertration Atmos- No. tion ature,F. (percent phere Time in Ethyl (Alcohol) 75 20 Air 1min. 75 20 d0 5min. 75 20 do 20min. 75 2O Nitrogen 1min. 75 20 d0 5min. 75 Air 5min. 100 20 do 5min. 00-70 20 d0... 5min. 75 20 .do lhour 75 20 do 5hours 75 20 do ltihours 75 20 Nitrogen lhour 75 20 do 4hours 75 100 Air 4hours 100 20 do 4hours 60-70 20 do 4hours 1 The frequency for all examples was 1 megacycle.

2 The plate current reading for all experiments with cavitation was 200 milliamperes and for all experiments vwthout; cavitation was milliamperes.

3 The nitrogen atmosphere was provided by applying a very low pressure jet of the gas to the inside of the test tube.

4 No solvent.

Table N 0. II

COMPARISON OF TREATED PERFUMES Comparison Comments Between Heavy Oriental Type Perfume No. 2 and No. 17 No. 2 has more top note of the iougere, i.e.,

citrus; No. 17 has more depth and body.

No. 2 and No. 4 N o. 4 is definitely more pleasant, more mellowed.

N o. 7 and N o. 15.-. Very slight difference only in favor of No. 15

which seems to be more flowery.

No. 9 and No. 15. Strong difference. Top note is more subdued in No. 9 than in No. 15.

N o. 2 and No. 10 No. 10 has a better top note," has'rnore mellowness, body and sweetness, and is more pleasant perfume of the same general character.

Light, Flowery Type Perfume No. 2 and No. 10. No. 10 is stronger, loss aldehydic, with mor depth and a better top note.

No. 2 and No. l3 No. 13 is slightly less aldehydic; has more depth strength and a better and more flowery top note.

No. 3 and No. 6 Slight difference only; No. 6 seems to have taken on a little age, a little mellowness.

No. 2 and N o. 13 No. 13 is less aldehydic and of deeper and stronger character.

No. 7 and No. 15. Difierent. No. 15 is more pleasant,more mellow,

sweeter and more flowery.

While no particular emphasis can be or is given to these comments, they do represent the judgment of qualified experts and, thus, may be of considerable guidance to similar experts who are attempting to practice the invention.

A further and more complete indication of the nature of the changes that may be expected is presented pictorially in FIGS. 1 and 2, FIG. 1 being for the light aldehyde type perfume and FIG. 2 being for the heavy oriental type. In these figures, lines connect the pairs of the experiments of Table I that were compared with the letter between the arrow heads in the line indicating the extent of the difference noted. The letter 0 denotes a small change, the letter m a minor change and the letter s a strong change.

It will be apparent that the technique of the present invention is a significant contribution to the art of perfumery in that it makes available to the perfumer literally innumerable new odor notes in perfumes that were previously unavailable or could be obtained only by careful and patient combination of existing materials. In addition, these new notes can be produced simply and inexpensively in a relatively short period of time. Further, an advantage of the new technique is that it could very well permit new notes to be synthesized systematically to satisfy a particular demand when it arises. The treated materials, of course, can be blended with others, treated or untreated, and when this fact is kept in mind one can readily comprehend the endless number of new combinations that are hereby provided.

In order to illustrate the type of apparatus that can be utilized to effect the treatment heretofore described, two satisfactory forms of such an apparatus are depicted schematically in FIGS. 3 and 4, in which FIG. 3 is a side elevation in cross-section of a one cell system; and FIG. 2 is a side elevation in the cross-section of a multi-cell system.

Referring now to FIG. 3, the numeral designates a supply or feeder tank, constructed of any suitable metal, such as copper, aluminum or stainless steel, which is in communication by way of a syphon tube 11 with a treatment tank 12. The treatment tank is preferably formed of stainless steel as thin as possible, at least on the bottom, to permit maximum transmission of vibrations and is nestled within a larger tank 13, being maintained in spaced relationship with the larger tank by means of coil springs 14 or the like. Tank 13 may be of relatively heavy construction and in use is filled with a non-compressible fluid adapted for the transmission of vibrations. For most purposes water constitutes a suitable fluid but in the cases where it is desired to carry out the treatment at extreme levels of temperature, there may be substituted in lieu of water any inert fluid having a higher boiling point or lower freezing point than Water, as desired. To permit the adjustment of the temperature in the liquid in treatment tank 12 a coil 15 is disposed therein through which may be passed a suitable heat exchange medium heated or cooled to the appropriate temperature. Mounted on the floor of the larger tank 13 are a plurality of vibratory units or transducers 16 which are connected by means, not shown, to a suitable source of power, also not shown. The number of transducers that are employed is dictated largely by the volume of fluid that is to be treated. An outlet spigot 18 is provided in one Wall of tank 13 to enable the tank to be readily emptied. An outlet syphon tube 19 extends from the treatment tank 12 to a receiving tank 20 into which the fluid is discharged following treatment. Tank 20 is also equipped with a discharge spigot, as at 21.

The multi-cell system of FIG. 4 is basically similar to the single cell unit of FIG. 3, with the exception that treatment tank 12 is divided by a plurality of baffies 23 into a number of compartments. Preferably, baffles 23 are so arranged as to cause alternate top and bottom flow etween the cells, which is to say that the fluid being treated flows over the top of one baffie and underneath the bottom of the next in passing through the series of cells. A syphon tube 24, having a valve 25 at the lower end may extend into each of the cells, thereby permitting fluid to be withdrawn at any stage of the treatment. It will also be observed that the feed from supply tank 10 is of the simple gravity flow type through pipe 11'. The remaining elements correspond generally to the elements discussed with the single cell unit and will not be redescribed here, although prime designations are given for those elements to indicate such correspondence.

Both of the systems illustrated and described are adapted for either batch or continuous processing. In the first instance, the desired volume of the material to be processed is admitted into the inner treatment tank 12. Power is then supplied to the transducers for the desired period of time and, after the end of this period, the vibration is halted and the treated material withdrawn from the tank. In the second instance, the fluid material is continuously discharged into one end and withdrawn from the other end of treatment tank 12, with the rates of flow at these two points being adjusted to provide a dwell of the fluid within the tank of the given period. The operation of both units is quite simple and is deemed to require no further explanation.

It will be understood that in addition to the two apparatus just described, any other apparatus or container designed and adapted for use in operations involving sound waves can be used with more or less efficiency. For instance, the number of transducer heads provided at the bottom of the reaction vessel can be varied as desired and virtually any commercially available transducer may be utilized, including immersion type transducers. Examples of suitable transducers are the following types: piezoelcctric (electro-strictive), magneto-strictive, or electrodynamic. As a precautionary measure, the transducer may be isolated from the perfume by a sheet metal partition or barrier, preferably of stainless steel or other non-reactive metal, to protect the transducer head from chemical attack and to protect the perfume as Well, alhough this is not necessary with immersion transducers which have a radiating surface of Monel metal, stainless steel, or more other inert material. Where advantageous, the treatment of this invention may be carried out in the presence of ultra-violet rays, as suggested in the Ioffre patent, already referred to. Where the materials being treated are in solid or crystalline form, the apparatus described in our co-pending application, Serial No. 573,487, filed March 23, 1956, is suitable.

Those skilled in the arts will be aware, as the description of the invention indicates, that the practice of the invention is subject to a wide variation. Where specific deails are stated, it is for the purpose of exemplifying the invention and facilitating an understanding thereof and not for the purpose of restricting its scope.

Having thus described the invention, that which is claimed is:

1. In a method of preparing a perfume comprising at least one perfumery material, the improvement of treating said material in a form selected from the group consisting of a substantially solvent-free liquid and a solution in at least one solvent of the group consisting of ethyl alcohol and diethyl phthalate in an inert container to sound waves having a frequency of at least 50 cycles per second for a time of at least one minute, said time and frequency having an inverse relationship and being suflicient to alter and improve the odor characteristics of said material.

2. The method of claim 1 wherein said sound waves have a frequency of at least 20,000 cycles per second.

3. The method of claim 1 including the step of admixing said treated perfumery material with a perfumery material which has not been so treated.

4. The method of claim 1 wherein said sound waves are such as to cause cavitation in said material.

5. The method of claim 1 wherein the treatment is carried out at a temperature above the crystallization temperatures of the material but below the minimum boiling point thereof.

6. The method of claim 1 wherein the treatment is carried out in a nitrogen atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 2,086,891 Bachmann July 13, 1937 2,109,151 Krause Feb. 22, 1938 2,196,193 Chamber Apr. 9, 1940 2,473,453 Shropshire June 14, 1949 (Other references on following page) Food Engineering, August 1953, p. 166.

9 10 UNITED STATES PATENTS Vigoureux: Ultrasonics, Chapman and Hall, Ltd.,

Romagnon June 14, 1952 London, 1950, pp. 78-141.

Jofire May 25, 1954 Carlin: Ultrasonics, McGraw-Hill, New York, 1st Ed.,

FOREIGN PATENTS 5 PP- f 9- A t Ya Se t 17 1929 Ultrasonlcs, American Institute of Chem. Eng., Chem.

f i g 1939 Eng. Progress Symposium, No. 1, vol. 47, 1951, p. 66.

Moncrief: The Chem. of Perf. Materials, United Trade OTHER REFERENCES Press Ltd., 1949, p. 61. 

1. A METHOD OF PREPARING A PREFUNE COMPRISING AT LEAST ONE PERFUMERY MATERIAL, THE IMPROVEMENT OF TREATING SAID MATERIAL IN A FORM SELECTED FROM THE GROUP CONSISTING OF A SUBSTANTIALLY SOLVENT-FREE LIQUID AND A SOLUTION IN AT LEAST ONE SOLVENT OF THE GROUP CONSISTING OF ETHYL ALCOHOL AND DIETHYL PHTHALATE IN AN INERT CONTAINER TO SOUND WAVES HAVING A FREQUENCY OF AT LEAST 50 CYCLES PER SECOND FOR A TIME OF AT LEAST ONE MINUTE, AND TIME AND FREQUENCY HAVING AN INVERSE RELATIONSHIP AND BEING SUFFICIENT TO ALTER AND IMPROVE THE ODOR CHARACTERISTICS OF SAID MATERIAL. 